1. Field of the Invention
The present invention relates to a battery case attachment unit and, more specifically, to an attaching unit of a battery case used for a head lamp and the like for a component for bicycles and motorcycles.
2. Description of the Background Art
FIG. 7 is a cross section showing a conventional structure of a head lamp attached to a part of a bicycle. Referring to the figure, a bulb 17 for illuminating ahead through a lens unit 5 is contained in the left side portion of head lamp body 1, while a battery case 3 accommodating a battery therein is accommodated in a battery case housing 4 of the head lamp body 1 on the right side of the figure.
A bracket 7 which is fixed on a handle or the like of the bicycle includes an attaching piece 11 and an attaching piece 13 rotatable around a pin 9, which attaching pieces are fastened to the handle or the like by means of a bolt 14. The head lamp body 1 can be slidably attached on the bracket 7 by fitting on a rail-like protrusion 21 provided on the top surface of the bracket 7 with a groove 19 provided at the lower surface of the head lamp body 1. A stopper 23 is provided between a stopper holding portion 24 on the lower surface of battery case housing 4 of head lamp body 1 and a lower surface of an inserting portion 33 of the accommodated battery case 3. Stopper 23 is formed of an resilient body such as ebonite, and it has a cross section of a vertical V with a protrusion 25 being at or proximate the center.
Attaching and detaching operations of battery case 3 to head lamp body 1 will be described.
After the battery is accommodated therein, battery case 3 is gradually inserted into the battery case housing 4 of head lamp body 1. Before the insertion of battery case 3, protrusion 25 is located at an upper portion. However, when an end portion of battery case 3 is brought into contact with projection 25 as battery case 3 is inserted, protrusion 25 of stopper 23 moves downward against its resiliency. When insertion of battery case 3 is completed in this state, a recess 26 provided at an inserting portion 33 of battery case 3 is positioned corresponding to protrusion 25 of stopper 23. At that position, protrusion 25 of stopper 23 is fixed in recess 26 of battery case 3, and the original shape of stopper 23 is resumed. Thus slipping of battery case 3 from head lamp body 1 can be prevented by the resilient action of stopper 23.
In the conventional battery case attaching unit as described above, what prevents slipping of battery case 3 from head lamp body 1 is only the resilient force of stopper 23. Therefore, if a strong vibration or the like is exerted on head lamp body 1 and such a large force is applied in the direction of slipping of battery case 3 as to exceed the resilient force of stopper 23, battery case 3 may possibly be slipped from head lamp body 1.